As the stolen memory region will contain the contents of whatever was
last there, it invariably contains garbage. To be consistent with the
shmemfs backed fb and the expectations of the fb layer, we need to clear
the fb prior to installing it as an fbcon.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=58111Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Fixup sparse __iomem confusion reported by Wu Fengguang.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We ignore all the user requests to handle flushing to the GTT domain if
the user requests such on a snoopable bo, and as such access through the
GTT to such pages remains incoherent. The specs even warn that such
behaviour is undefined - a strong reason never to do so.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The function doesn't use any of the registers mentioned, nor does it
return true or false. Hard to do worse. Remove it, the function is
absolutely descriptive enough to not need any comment.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

CPT+ PCHs have different bit definition to read the HPD live status. I
don't have an ILK with digital ports handy, which is why this patch is
separate from the CPT+ implementation. If the docs don't lie, it should
all be fine though.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Moving the DPCD just after a successful read will allow to:
  - log all DPCD reads (eDP ones, changes signalled by HPD IRQ)
  - don't log it if we haven't been able to read it

v2: Be sure to log the DPCD when a downstream port does not have HPD
    support and the branch device asserts HPD (Jani Nikula)
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Just like:

  Author: Damien Lespiau <damien.lespiau@intel.com>
  Date:   Wed Dec 12 19:37:22 2012 +0000

      drm/i915/hdmi: Read the HPD status before trying to read the EDID

But this time for DiplayPort.

v2: Adapt to the ibx_ name change and don't add commit hash (Chris
Wilson, Jani Nikula)
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If you unplug the hdmi connector slowly enough, the hotplug interrupt
fires but then the kernel code tries to read the EDID and succeeds
(because the connector is still half connected, the HPD pin is shorter
than the others, and DDC works). Since EDID succeeds it thinks the
monitor is still connected.

To prevent that, read the live HPD status in the hotplug handler before
trying to read the EDID.

v2: Rename the function to ibx_ (Chris Wilson)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=55372Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Those status bits don't follow the usual pattern: _MASK (those bits are
write 1 to clear, useful to select the value we want to read) and the
values shifted by the same amount.

Cleaned that that up when poking at the register for testing purposes,
might as well upstream that cleanup.
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Spinning for up to 200 us with interrupts locked out is not good. So
let's just spin (and even that seems to be excessive).

And we don't call these functions from interrupt context, so this is
not required. Besides that doing anything in interrupt contexts which
might take a few hundred us is a no-go. So just convert the entire
thing to a mutex. Also move the mutex-grabbing out of the read/write
functions (add a WARN_ON(!is_locked)) instead) since all callers are
nicely grouped together.

Finally the real motivation for this change: Dont grab the modeset
mutex in the dpio debugfs file, we don't need that consistency. And
correctness of the dpio interface is ensured with the dpio_lock.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For GMCH platforms we set up the hpd irq registers in the irq
postinstall hook. But since we only enable the irq sources we actually
need in PORT_HOTPLUG_EN/STATUS, taking dev_priv->hotplug_supported_mask
into account, no hpd interrupt sources is enabled since

commit 52d7eced
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Sat Dec 1 21:03:22 2012 +0100

    drm/i915: reorder setup sequence to have irqs for output setup

Wrongly set-up interrupts also lead to broken hw-based load-detection
on at least GM45, resulting in ghost VGA/TV-out outputs.

To fix this, delay the hotplug register setup until after all outputs
are set up, by moving it into a new dev_priv->display.hpd_irq_callback.
We might also move the PCH_SPLIT platforms to such a setup eventually.

Another funny part is that we need to delay the fbdev initial config
probing until after the hpd regs are setup, for otherwise it'll detect
ghost outputs. But we can only enable the hpd interrupt handling
itself (and the output polling) _after_ that initial scan, due to
massive locking brain-damage in the fbdev setup code. Add a big
comment to explain this cute little dragon lair.

v2: Encapsulate all the fbdev handling by wrapping the move call into
intel_fbdev_initial_config in intel_fb.c. Requested by Chris Wilson.

v3: Applied bikeshed from Jesse Barnes.

v4: Imre Deak noticed that we also need to call intel_hpd_init after
the drm_irqinstall calls in the gpu reset and resume paths - otherwise
hotplug will be broken. Also improve the comment a bit about why
hpd_init needs to be called before we set up the initial fbdev config.

Bugzilla: Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=54943Reported-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> (v3)
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

To gain confidence in the wrap handling, make it happen quite
soon after the boot.
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The complication is that during seqno wrapping we must be extremely
careful not to write to any ring as that will require a new seqno, and
so would recurse back into the seqno wrap handler. So we cannot call
i915_gpu_idle() as that does additional work beyond simply retiring the
current set of requests, and instead must do the minimal work ourselves
during seqno wrapping.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If wrap just happened we need to prevent emitting waits for
pre wrap values. Detect this and emit no-ops instead.

v2: Use olr > seqno to detect wrap instead of *seqno == 0
as suggested by Chris Wilson.

v3: Use last used seqno to detect the wraparound. From
Chris Wilson

v4: Fixed unnecessary last_seqno assigment

References: https://bugs.freedesktop.org/show_bug.cgi?id=57967Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

smatch warning:

drivers/gpu/drm/i915/intel_display.c:7019 intel_set_mode() warn: function puts
500 bytes on stack

Refactor so that saved_mode and saved_hwmode are dynamically allocated as opposed
to being automatic variables. 500 bytes seems like it could run the potential for blowing
the kernel stack.

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: NTim Gardner <tim.gardner@canonical.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drm/drm_edid.h was included twice.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Commit 9ee32fea unconditionally prevents the CPU from entering idle states
until intel_dp_aux_ch completes for the first time, which never happens on my
DisplayPort-less intel gfx, causing the CPU to get rather hot.
Signed-off-by: NTomas Janousek <tomi@nomi.cz>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On a machine with bit17 swizzling, we need to store the bit17 of the
physical page address in put-pages. This requires a memory allocation,
on average less than a page, which may be difficult to satisfy is the
request to put-pages is on behalf of the shrinker. We could allow that
allocation to pull from the reserved memory pools, but it seems much
safer to preallocate the array for tiled objects on affected machines.

v2: Export i915_gem_object_needs_bit17_swizzle() for reuse.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Both the dp and fdi code use the exact same computations (ignore minor
differences in conversion between bits and bytes).

This makes it even more apparent that we have a _massive_ mess between
cpu transcoder/fdi link/pch transcoder and pch link settings. And also
that we have hilarious amounts of confusion between edp and dp
(despite that they're identical at a link level).
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This has originally been added in

commit 8db9d77b
Author: Zhenyu Wang <zhenyuw@linux.intel.com>
Date:   Wed Apr 7 16:15:54 2010 +0800

    drm/i915: Support for Cougarpoint PCH display pipeline

probably to combat issues with hw state left behind by the BIOS. And
indeed, I've checked out that specific revision, and there is no DP
support yet. So the pch dp transcoder won't be correctly disabled, and
that's important since it requires a rether special disable dance:
Just writing 0 to TRANS_DP_CTL won't cut it, since we need to select
the NONE port when disabling, too.

And indeed, things seem to still work, so let's just remove this.
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This could have happened with the old crtc helper based modeset code,
but can't happen any longer with the new code.

Hence put in a WARN and adjust the comment. If no one hits this, we
can eventually remove it (like a few other such cases across our
code).
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

17 ms is eerily close to 60 Hz ^-1

Unfortunately this goes back to the original DP enabling for ilk, and
unfortunately does not come with a reason for it's existance attached.

Some closer inspection of the code and DP specs shows that we set the
idle link pattern before we disable the port. And it seems like that
the DP spec (or at least our hw) only switch to the idle pattern on
the next vblank. Hence a vblank wait at this spot makes _much_ more
sense than a really long wait.

v2: Rebase fixup.

v3: Add comment requested by Paulo Zanoni saying that we don't really
know what this wait is for.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

While reading docs I've noticed that this special workaround to select
the 1.6 GHz DP clock only applies to pre-production ilk machines.
Since the registers we're touching here are rather undocumented and
might be harmful on later chips, rip it out.

For the Bspec reference of this w/a look in "vol4g CPU Display
Registers [DevILK]", Section 4.1.7.1 "DP_A—DisplayPort A
Control Register", "DP_PLL_Frequency_Select".

v2: Keep a debug message as a hint in case something regresses.
Requested by Chris Wilson.
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that we enable the cpu edp pll in intel_dp->pre_enable and no
longer in crtc_mode_set, we can also move the modeset part to the
intel_dp->mode_set callback. Previously this was not possible because
the encoder ->mode_set callbacks are called after the crtc mode set
callback.

v2: Rebase on top of copy&pasted hsw crtc_mode_set.
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Especially getting rid of all things lvds is ... great!

v2: Drop the two additional pre-hsw hunks noticed by Paulo Zanoni.

v3:
- handle DP ports correctly (spoted by Paulo)
- don't leave {} behind for a single-line block (again spotted by
  Paulo)
- kill another if (IBX || CPT) block
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Having 9500 lines repeated on dmesg does not help me at all.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

TRANS_DP_VIDEO_AUDIO is not used at all.
The other 3 has duplicated #defines.
Signed-off-by: NDexuan Cui <dexuan.cui@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Less clutter in the traces. And in both cases we yell rather loud
into the logs if we time out. Patch suggested by Chris Wilson.

v2: Annotate another I915_READ in dp_aux to be consistent - we filter
out all register io in wait_for and similar loops. Chris also
suggested to mark all dp_aux register access as _NOTRACE, but I think
we should keep all functionally relevant access around, and filter
unneeded bits in userspace after the trace is captured.
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

At least on the platforms that have a dp aux irq and also have it
enabled - vlvhsw should have one, too. But I don't have a machine to
test this on. Judging from docs there's no dp aux interrupt for gm45.

Also, I only have an ivb cpu edp machine, so the dp aux A code for
snb/ilk is untested.

For dpcd probing when nothing is connected it slashes about 5ms of cpu
time (cpu time is now negligible), which agrees with 3 * 5 400 usec
timeouts.

A previous version of this patch increases the time required to go
through the dp_detect cycle (which includes reading the edid) from
around 33 ms to around 40 ms. Experiments indicated that this is
purely due to the irq latency - the hw doesn't allow us to queue up
dp aux transactions and hence irq latency directly affects throughput.
gmbus is much better, there we have a 8 byte buffer, and we get the
irq once another 4 bytes can be queued up.

But by using the pm_qos interface to request the lowest possible cpu
wake-up latency this slowdown completely disappeared.

Since all our output detection logic is single-threaded with the
mode_config mutex right now anyway, I've decide not ot play fancy and
to just reuse the gmbus wait queue. But this would definitely prep the
way to run dp detection on different ports in parallel

v2: Add a timeout for dp aux transfers when using interrupts - the hw
_does_  prevent this with the hw-based 400 usec timeout, but if the
irq somehow doesn't arrive we're screwed. Lesson learned while
developing this ;-)

v3: While at it also convert the busy-loop to wait_for_atomic, so that
we don't run the risk of an infinite loop any more.

v4: Ensure we have the smallest possible irq latency by using the
pm_qos interface.

v5: Add a comment to the code to explain why we frob pm_qos. Suggested
by Chris Wilson.

v6: Disable dp irq for vlv, that's easier than trying to get at docs
and hw.

v7: Squash in a fix for Haswell that Paulo Zanoni tracked down - the
dp aux registers aren't at a fixed offset any more, but can be on the
PCH while the DP port is on the cpu die.

Reviewed-by: Imre Deak <imre.deak@intel.com> (v6)
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Doesn't do anything yet than call dp_aux_irq_handler.
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

GMBUS_ACTIVE has inverted sense and so doesn't fit into the
wait_hw_status helper, hence create a new gmbus_wait_idle functions.
Also, we only care about the idle irq event and nothing else, which
allows us to use the wait_event_timeout helper directly without
jumping through hoops to catch NAKs.

Since gen2/3 don't have gmbus interrupts, handle them separately with
the old wait_for macro.

This shaves another few ms off reading EDID from a hdmi screen on my
testbox here. EDID reading with interrupt driven gmbus is now as fast
as with busy-looping gmbus at 28 ms here (with negligible cpu
overhead).
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We need two special things to properly wire this up:
- Add another argument to gmbus_wait_hw_status to pass in the
  correct interrupt bit in gmbus4.
- Since we can only get an irq for one of the two events we want,
  hand-roll the wait_event_timeout code so that we wake up every
  jiffie and can check for NAKs. This way we also subsume gmbus
  support for platforms without interrupts (or where those are not
  yet enabled).

The important bit really is to only enable one gmbus interrupt source
at the same time - with that piece of lore figured out, this seems to
work flawlessly.

Ben Widawsky rightfully complained the lack of measurements for the
claimed benefits (especially since the first version was actually
broken and fell back to bit-banging). Previously reading the 256 byte
hdmi EDID takes about 72 ms here. With this patch it's down to 33 ms.
Given that transfering the 256 bytes over i2c at wire speed takes
20.5ms alone, the reduction in additional overhead is rather nice.

v2: Chris Wilson wondered whether GMBUS4 might contain some set bits
when booting up an hence result in some spurious interrupts. Since we
clear GMBUS4 after every wait and we do gmbus transfer really early in
the setup sequence to detect displays the window is small, but still
be paranoid and clear it properly.

v3: Clarify the comment that gmbus irq generation can only support one
kind of event, why it bothers us and how we work around that limit.

Cc: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Only enables the interrupt and puts a irq handler into place, doesn't
do anything yet.

Unfortunately there's no gmbus interrupt support for gen2/3 (safe for
pnv, but there the irq is marked as "Test mode").

v2: Wire up the irq handler for vlv and gen4 properly.

v3: i915_enable_pipestat expects the mask bit, not the status bits ... and
for added hilarity those are rather inconsistently named.
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The gmbus interrupt generation is rather fiddly: We can only ever
enable one interrupt source (but we always want to check for NAK
in addition to the real bit). And the bits in the gmbus status
register don't map at all to the bis in the irq register.

To prepare for this mess, start by extracting the hw status wait
loop into it's own function, consolidate the NAK error handling a
bit. To keep things flexible, pass in the status bit we care about
(in addition to any NAK signalling).

v2: I've failed to notice that the sense of GMBUS_ACTIVE is inverted,
Chris Wilson gladly pointed that out for me. To keep things simple,
ignore that case for  now (we only need to idle the gmbus controller
at the end of an entire i2c transaction, not after every message).
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Otherwise the new&shiny irq-driven gmbus and dp aux code won't work that
well. Noticed since the dp aux code doesn't have an automatic fallback
with a timeout (since the hw provides for that already).

v2: Simple move drm_irq_install before intel_modeset_gem_init, as
suggested by Ben Widawsky.

v3: Now that interrupts are enabled before all connectors are fully
set up, we might fall over serving a HPD interrupt while things are
still being set up. Instead of jumping through massive hoops and
complicating the code with a separate hpd irq enable step, simply
block out the hotplug work item from doing anything until things are
in place.

v4: Actually, we can enable hotplug processing only after the fbdev is
fully set up, since we call down into the fbdev from the hotplug work
functions. So stick the hpd enabling right next to the poll helper
initialization.

v5: We need to enable irqs before intel_modeset_init, since that
function sets up the outputs.

v6: Fixup cleanup sequence, too.
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

... together with all the other irq related resources in
intel_irq_init. I've managed to oops in the notify_ring function on my
ilk, presumably because of the powerctx setup call to i915_gpu_idle.

Note that this is only a problem with the reorder irq setup sequence
for irq-driver gmbus/dp aux.
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is for legacy legacy stuff, and checking with the leftover
pipe from the previous loop is propably not what we want. Since
pipe == 2 after the loop ... Then we only assing a variable and do
nothing with it.

Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

No need to have the exaxt same code twice.
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If there are pre-wrap values in semaphore-mbox registers after wrap,
syncing against some after-wrap request will complete immediately.
Fix this by emitting ring commands to set mbox registers to zero
when the wrap happens.

v2: Use __intel_ring_begin to emit ring commands, from
Chris Wilson.
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Add a small comment to handle_seqno_wrap.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In preparation for handling ring seqno wrapping, split
intel_ring_begin into helper part which doesn't allocate
seqno.
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

seqno's are u32 so print accordingly
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>